From patchwork Tue Jan 10 18:03:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 13095457 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09DCBC61DB3 for ; Tue, 10 Jan 2023 18:12:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238802AbjAJSMY (ORCPT ); Tue, 10 Jan 2023 13:12:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238829AbjAJSL6 (ORCPT ); Tue, 10 Jan 2023 13:11:58 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BCB9B56; Tue, 10 Jan 2023 10:10:31 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DB5556182C; Tue, 10 Jan 2023 18:10:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2930C433D2; Tue, 10 Jan 2023 18:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673374230; bh=9NdXOmkiTVBp0bp3bFhoadq9j659g/3HfDuElJpJhKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cvlFK+1x92rmHO2nxfUAJvbotJePTGcpR1jm7m28GZrpBvCjGjOdXBM4LhEfAt0nN 9ErglWA15vvDaIrvDcBHvTh4bgopmOTG1NxGj241WlGxDUFtmf0xBMD590fQ0XVGws 7NRfbVtkfrJJ1G0zse+ng1W24KYlvRjn0RfNuTmE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Namhyung Kim , Arnaldo Carvalho de Melo , Adrian Hunter , bpf@vger.kernel.org, Ian Rogers , Ingo Molnar , Jiri Olsa , Peter Zijlstra , Song Liu , Sasha Levin Subject: [PATCH 6.0 094/148] perf stat: Fix handling of --for-each-cgroup with --bpf-counters to match non BPF mode Date: Tue, 10 Jan 2023 19:03:18 +0100 Message-Id: <20230110180020.176795133@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230110180017.145591678@linuxfoundation.org> References: <20230110180017.145591678@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Namhyung Kim [ Upstream commit 54b353a20c7e8be98414754f5aff98c8a68fcc1f ] The --for-each-cgroup can have the same cgroup multiple times, but this confuses BPF counters (since they have the same cgroup id), making only the last cgroup events to be counted. Let's check the cgroup name before adding a new entry to the cgroups list. Before: $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1 Performance counter stats for 'system wide': msec cpu-clock / context-switches / cpu-migrations / page-faults / cycles / instructions / branches / branch-misses / 8,016.04 msec cpu-clock / # 7.998 CPUs utilized 6,152 context-switches / # 767.461 /sec 250 cpu-migrations / # 31.187 /sec 442 page-faults / # 55.139 /sec 613,111,487 cycles / # 0.076 GHz 280,599,604 instructions / # 0.46 insn per cycle 57,692,724 branches / # 7.197 M/sec 3,385,168 branch-misses / # 5.87% of all branches 1.002220125 seconds time elapsed After it becomes similar to the non-BPF mode: $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1 Performance counter stats for 'system wide': 8,013.38 msec cpu-clock / # 7.998 CPUs utilized 6,859 context-switches / # 855.944 /sec 334 cpu-migrations / # 41.680 /sec 345 page-faults / # 43.053 /sec 782,326,119 cycles / # 0.098 GHz 471,645,724 instructions / # 0.60 insn per cycle 94,963,430 branches / # 11.851 M/sec 3,685,511 branch-misses / # 3.88% of all branches 1.001864539 seconds time elapsed Committer notes: As a reminder, to test with BPF counters one has to use BUILD_BPF_SKEL=1 in the make command line and have clang/llvm installed when building perf, otherwise the --bpf-counters option will not be available: # perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1 Error: unknown option `bpf-counters' Usage: perf stat [] [] -a, --all-cpus system-wide collection from all CPUs # Fixes: bb1c15b60b981d10 ("perf stat: Support regex pattern in --for-each-cgroup") Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: bpf@vger.kernel.org Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Link: https://lore.kernel.org/r/20230104064402.1551516-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/cgroup.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index e99b41f9be45..cd978c240e0d 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -224,6 +224,19 @@ static int add_cgroup_name(const char *fpath, const struct stat *sb __maybe_unus return 0; } +static int check_and_add_cgroup_name(const char *fpath) +{ + struct cgroup_name *cn; + + list_for_each_entry(cn, &cgroup_list, list) { + if (!strcmp(cn->name, fpath)) + return 0; + } + + /* pretend if it's added by ftw() */ + return add_cgroup_name(fpath, NULL, FTW_D, NULL); +} + static void release_cgroup_list(void) { struct cgroup_name *cn; @@ -242,7 +255,7 @@ static int list_cgroups(const char *str) struct cgroup_name *cn; char *s; - /* use given name as is - for testing purpose */ + /* use given name as is when no regex is given */ for (;;) { p = strchr(str, ','); e = p ? p : eos; @@ -253,13 +266,13 @@ static int list_cgroups(const char *str) s = strndup(str, e - str); if (!s) return -1; - /* pretend if it's added by ftw() */ - ret = add_cgroup_name(s, NULL, FTW_D, NULL); + + ret = check_and_add_cgroup_name(s); free(s); - if (ret) + if (ret < 0) return -1; } else { - if (add_cgroup_name("", NULL, FTW_D, NULL) < 0) + if (check_and_add_cgroup_name("/") < 0) return -1; }